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256                           Governor Details.

Central Weight E is fastened to the table of a horizontal
boring machine, as shewn at N, Fig. 262, and bored with cutters
of correct radius. It is next put on a mandrel fitting the smaller
hole, and the outside turned to template. First the ends are
faced, then the diameter turned as a cylinder, and the rest is
obtained by various angular feeds, finishing by hand. The key-
way for fastening to sleeve B is to be slotted. The Bush F for
the weight, is to be bored in a chuck, and then turned on a
special mandrel, shewn at p, Fig. 262, being afterwards driven
tightly into the weight by means of a copper hammer. The
Nuts and Guard G are first bored, and afterwards turned on a
mandrel, being replaced in the chuck for screwing. The tooling
of the Lever H may be understood by reference to the regulator
lever No. I., and the studs j j are all examples of simple turning
and screwing. The Lifting Link K, and the Lifting Eye M,
need no special description. (See App. I. and //.,//. 753 and820.)
We now come to the Mitre Wheels L. For the machining
of these we may again refer to Fig. 262. Both wheels are made
of gun-metal and are exactly alike, boss included. After boring
truly they are placed on a mandrel, and the < blank' turned as at
A to a template which has been previously made with great care.
The teeth are then to be cut by means of a milling cutter. A
mandrel is provided which fits into the socket of the dividing
centre shewn at D, and the wheel set at such an angle that the
lower line of the tooth, ef, is horizontal. Looking in front of the
wheel, the work must be1 set so that one edge of the milling cutter
is in line with the centre. The radius <% of the cutter at c being
.made to fit the curve a of the larger end of the tooth, as shewn
at B, and the width bħ of the bottom of the cutter made equal to b
at the narrow end of the teeth; a little consideration will shew
that the cutter will trim up one side of the tooth in such a way
that the smaller ends of the teeth d will be a little too wide at
this point, as shewn at* G. After all the spaces have been cut out
as at D and one side of the tooth, the work is traversed forward
and the other face cut as at B, after which the taper c of the teeth
is lined out as at G, using (i) a straight edge of tht forni shewn at
F, page 62; and (2) a template F, Fig. 262, These surfaces are then
dressed off with the file. (See App. Z, /£, ^pp- 753, 823,986.)